Distinct Patterns of Fiber Type Adaptation in Rat Hindlimb Muscles 4 Weeks After Hemorrhagic Stroke.

Objective: The aim of this study was to evaluate adaptations in soleus and tibialis anterior muscles in a rat model 4 wks after hemorrhagic stroke.

Design: Young adult Sprague Dawley rats were randomly assigned to two groups: stroke and control, with eight soleus and eight tibialis anterior muscles per group. Hemorrhagic stroke was induced in the right caudoputamen of the stroke rats.

Skeletal muscle plasticity after hemorrhagic stroke in rats: influence of spontaneous physical activity.

Objective: The aim of this study was to determine the contribution of spontaneous post-stroke physical activity to skeletal muscle plasticity after stroke.

Design: A randomized controlled study was conducted of 24 young adult male Sprague-Dawley rats assigned to three experimental groups: (1) STR-hemorrhagic stroke in the right caudoputamen; (2) SHAM-procedural control; and (3) CONT-no intervention (n = 8/group). Neurologic testing was performed before and 2 wks after stroke.

Influence of insulin and muscle fiber type in nepsilon-(carboxymethyl)-lysine accumulation in soleus muscle of rats with streptozotocin-induced diabetes mellitus.

Background: Nepsilon-(carboxymethyl)-lysine (CML) is an advanced glycation end product (AGE), the accumulation of which has been implicated in the etiology of diabetes complications. Skeletal muscle in diabetes demonstrates altered function, and increased accumulation of CML has been found in several fast-twitch muscles of diabetic animals.

Objective: This study aims to explore the accumulation of CML in soleus (a slow muscle) in diabetic animals, with and without insulin therapy.

Advanced glycation end-product accumulation and associated protein modification in type II skeletal muscle with aging.

One mechanism that may influence the quality of skeletal muscle proteins, and explain the age-related decline in contractility, is protein damage. Advanced glycation end-products (AGE) in vivo are useful biomarkers of damage. In this study, comparison of extensor digitorum longus (EDL) muscles from young (8 months), old (33 months), and very old (36 months) Fischer 344 Brown Norway F1 (F344BNF1) hybrid rats shows that muscles from the very old rats have a significantly higher percentage of myofibers that immunolabel intracellularly for AGE-antibody 6D12 compared to the younger age group.

Advanced glycation end product in diabetic rat skeletal muscle in vivo.

Background: Advanced glycation end products (AGEs) are implicated in the etiology of diabetic complications in the kidney, nerve and eye. Skeletal muscle contractile parameters have also been found to be altered in diabetes. Glycation has not been extensively studied in skeletal muscle, but AGE-modified proteins may influence contractility.

Effect of endurance exercise on myosin heavy chain isoform expression in diabetic rats with peripheral neuropathy.

Objective: This study evaluated the effect of endurance exercise on myosin heavy chain (MHC) isoform expression in soleus muscle of diabetic rats with peripheral neuropathy.

Design: Male Sprague Dawley rats were randomly divided into four groups: control sedentary, diabetic sedentary, control exercise, and diabetic exercise. The exercised animals performed treadmill running five times per week.

Adult and developmental myosin heavy chain isoforms in soleus muscle of aging Fischer Brown Norway rat.

Fiber type shifts in aging skeletal muscle have been studied with myofibrillar ATPase histochemistry and gel electrophoresis, but less commonly with immunohistochemistry. Immunohistochemical study of myosin heavy chains (MHCs) in single myofibers yields additional information about aged skeletal muscle. Furthermore, many studies of aging rodent skeletal muscle have been performed on fast-MHC-predominant muscle and in several different strains.

Myosin heavy chain isoform immunolabelling in diabetic rats with peripheral neuropathy.

This study evaluated mature and immature myosin heavy chain (MHC) isoform immunolocalisation in soleus muscle of diabetic rats with documented motor neuropathy. Sprague Dawley rats were assigned to one of three groups: control (C), diabetic with insulin (DI), or diabetic without insulin (DNI). Twelve weeks after diabetes induction, soleus muscles were excised and quick-frozen.

Effects of endurance exercise-training on single-fiber contractile properties of insulin-treated streptozotocin-induced diabetic rats.

The purpose of this study was to characterize the contractile properties of individual skinned muscle fibers from insulin-treated streptozotocin-induced diabetic rats after an endurance exercise training program. We hypothesized that single-fiber contractile function would decrease in the diabetic sedentary rats and that endurance exercise would preserve the function. In the study, 28 rats were assigned to either a nondiabetic sedentary, a nondiabetic exercise, a diabetic sedentary, or a diabetic exercise group.

Muscle activity and aging affect myosin structural distribution and force generation in rat fibers.

The purpose of this study was to determine whether increased muscle activity could reverse myosin structural alterations that occur in aged rat muscle and whether those alterations could be induced in young rat muscle by decreased activity. Semimembranosus muscle activity was increased by electrical stimulation (200-ms trains, 154 Hz, 5 V) through a nerve cuff on the tibial branch of the ischiatic nerve. The protocol consisted of 5 sets of 6-10 maximal isometric contractions performed twice per week for 4 or 8-10 wk.